Sound resonating and amplifying attachment



April 30, 1935. J. P. TRUESDELL 1,999,919

SOUND RESONATING AND AMPLIF'YI NG ATTACHMENT Filed May 10, 1934 PatentedApr. 30, 1935 UNITED- STATES PATENT OFFICE I 1,999,919 scum) nasom'rmomama ATTACHMENT John P. Truesdell, R. I. Application May 10, 1934,Serial No. 725,004 g I p comin i (or mi-#21 I i This invention relatestoa soundresonating and: Arranged within the opening I is theattachamplifying attachment for use in connection with radio apparatus,and has for its object to provide, in a manner as hereinafter setforth'an attachment of the class referred to so positioned relative tothe speaker of the apparatus for increasing the volume and beauty oftone.

' Further objects of the invention are to provide,

in a manner as hereinafter set forth, an attachment for the purposereferred to, which is simpie in its construction, stro durable, compact,readily installed into the front of the cabinet'of the apparatus, injuxtaposition to the mouth of the speaker, thoroughly eflicient for thepurpose intended thereby and comparatively inexpensive.

To the above ends essentially, and to others which may hereinafterappear, the invention consists of such parts, and such combination ofparts:

as fall within the scope. of the invention as claimed. f 2

In the drawing: Figure 1v is a front elevation of. a radio apparatusshowing the adaptation therewith of a sound resonating and amplifyingattachment in accordance with this invention,

Figure 2 is a fragmentary view, partly, in vertical section and in sideelevation of the radio apparatus, showing the position. of one of theunits of the attachment with respect to the mouth of the speaker and thesound outlet opening in the front of they cabinet of the apparatus,

, Figure 3 is a fragmentary view, in'sectional plan of the radioapparatus showing the position of the attachment with respect to themouth end of the speaker, I

- Figure 4 is a perspective view showing the form employed of each unitof the attachment. 1

Thecabinet of a radio apparatus is generally indicated at 5 andincludesa front wall 6 formed with-a circular sound outlet opening 1.The outer part of the wall 8 of opening-l is rabbeted to form an endlessshoulder 9 and an endless ledge 10.

The wall 8 rearwardly of and in proximity to shoulder 9 is provided inthe lower part with a groove H having a rear "straight with and aforwardly inclined top wall terminating at the outer side of shou1der 9.The ends of groove ll v are closed and are arranged below and, inproximity to the horizontal median of opening 1.

Anchored to the inner face of the front wall 6, of the cabinet 5 is theflanged mouth end l2 of I the speaker l3. The flange on the latter isdesignated-M. The inner face of speaker l3 at its month end registerswith the inner portion of the wall 8 of opening I. v

of the tube.

ment, and the latter consists of a series of parlengthjtoextend from thelower portion of to a point between the horizontal median and the top ofthe opening 1'. Each unit'l6 is inthe form of a tube l1, open at eachend and having its ends oppositely beveled as at 18, I9. The bevels atthe ends of the tube ll' extend towards each other andprovide inconnection with the 1 rear portion or. the tube tapered rear portions20, 21' respectively at' the: upperv and lower ends The upper edge ofthe tube extends downwardly and forwardly from said tapered portion'20with respect to the rabbet on wall -8.' The lower edge of the tubeextends upwardly and forwardly from said tapered portion2l with respectto the rabbet on wall 8. Theforming of Ithe'endsof the tube; in a manneras stated providefor the rear portion of the latter to be'of'greaterlength than the front and major Dartjof the sides-thereof. The units l6forma set of resonators which'have open ends and their rear parts ofarlength to extend from within the lower portion. of wall. 8 to a pointspaced from the upper portion of thelatter. The number of the resonatorsof the set is such that the outer sides of 'theouter resonators of theset will abut diametrically opposed,v intermediate portions of ananchoring means for the units; The latter are anchored; in juxtapositionto and spaced slightly forward from the mouth of speaker l3. Thetaperedholding portion 2| of each tube is seated ingroove l I; The beveled endedges of the tube extend across and forwardly with ree spect to theouter sideof shoulder 9. I s v The tubesare anchored to partly extendacross opening I by a retainerr'nember 22 which binds against theholding portions 2|. The member 22 issecured by'anyjsuit'ablemeans tothe front wall 6 'and'abuts the shoulder! and ledge H3. The member 22 isflush with the outer face of front wall '6 and the inner portion of thewall 8. The major portionof the beveled ends of the tubesare spaced fromthe member 22. I I,

The; resonators of the set gradually increase in length from the outerones of the set to the 7 central one of the set. The outer resonators ofthe set have their outer sides bear against mem- 5 her 22. I I 0 ratushaving a loud speaker, said wall being 55 formed with a sound emittingopening, the rear of the wall of said opening registering throughoutwith the inner face of the speaker at the mouth of the latter, saidopening being circular, the wall of said opening being provided with anendless rabbet at its outer portion and a groove in the rear part of itslower portion in proximity to said rabbet, and a set of verticallydisposed tubular parallel sidewise abutting resonators within and ofless height than that of said opening, said resonators at their lowerends seating upon the lower portion of the wall of said opening, open ateach end and oppositely beveled at their ends to provide tapered holdingportions at the rear of their ends, said holding portions at the lowerends of said resonators corresponding in contour to and seated in saidgroove, means secured in said rabbet and coacting with said holdingportions at the lower ends of the resonators for anchoring the latter tosaid front wall to extend partly across said opening, the upper beveledends and the remaining portion of the lower beveled ends of saidresonators being spaced from and surrounded by said means, theresonators of said set gradually decreasing in length from the centralresonator of the set to the outer resonators of the set, the said outerresonators having their outer sides bearing against said means, and theupper ends of said resonators being flush with each other.

2. In a sound resonating and amplifying attachment for a radioapparatus, the combination of the cabinet of a radio apparatus havingits front wall provided with a sound emitting opening for registeringwith the loud speaker of the apparatus, a set of vertically disposedtubular parallel sidewise abutting resonators arranged in said opening,each of said resonators having a part of its lower end secured in thelower portion of the wall of said opening and its remaining part spacedfrom said lower portion, each of said resonators being open at each endthereof, and the height of said resonators being less than that of saidopening and having their upper ends flush with each other.

3. In a sound resonating and amplifying attachment for a radioapparatus, the combination of the cabinet of a radio apparatus havingits front wall provided with a sound emitting open ing for registeringwith the loud speaker of the apparatus, a set of vertically disposedtubular parallel sidewise abutting resonators arranged in said opening,said opening being circular, each of said resonators having a part ofits lower end anchored in the lower portion of the wall of said openingand its remaining part extending at an upwardly inclination and spacedfrom the lower portion of said wall, each of said resonators being openat each end and of a length less than the diameter of said opening, saidresonators having their upper ends flush with each other, and the outerresonators of said set sidewise abutting diametrically opposed portionsof said wall.

4. In a sound resonating and amplifying attachment for a radioapparatus, the combination of the cabinet of a radio apparatus havingits front wall provided with a sound emitting opening for registeringwith the loud speaker of the apparatus, a set of vertically disposedtubular parallel sidewise abutting resonators arranged in said opening,said opening being circular, each of said resonators having a part ofits lower end anchored in the lower portion of the wall of said openingand its remaining part extending at an upwardly inclination and spacedfrom the lower portion of said wall, each of said resonators being openat each end and of a length less than the diameters of said opening,said resonators having their upper ends flush with each other, and theouter resonators of said set sidewise abutting diametrically opposedportions of said wall, the upper ends of said resonators beingpositioned between the horizontal median of said opening and the top ofthe latter.

5. In a sound resonating and amplifying attachment for a radioapparatus, the combination of the cabinet of a radio apparatus havingits front wall provided with a sound emitting opening for registeringwith the loud speaker of the apparatus, a set of vertically disposedtubular parallel sidewise abutting resonators arranged in said opening,said opening being circular, each of said resonators having a part ofits lower end anchored in the lower portion of the wall of said openingand its remaining part extending at an upwardly inclination and spacedfrom the lower portion of said wall, each of said resonators being openat each end and of a length less than the diameter of said opening, saidresonators having their upper ends flush with each other, and the outerresonators of said set sidewise abutting diametrically opposed portionsof said wall, said resonators gradually increasing in height from thecentral resonator of said set to the outer resonators of said set, andthe upper ends of said resonators being positioned between the horizontal median of said opening and the top of the latter.

6. In a sound resonating and amplifying attachment for a radioapparatus, the combination of the cabinet of a radio apparatus havingits front wall provided with a sound emitting opening for registeringwith the loud speaker of the apparatus, a set of vertically disposedtubular sidewise abutting resonators arranged in and spaced from theinner end of said opening, each of said resonators being formed withoppositely beveled end edges, each resonator having its beveled upperedge extending rearwardly at an upward inclination from its front andits lower beveled rearwardly at a downward inclination from its front,the rear part of the lower edge of each resonator being anchored in thelower portion of the wall of said opening and the remaining part of saidlower edge being spaced from said portion, said resonators being open ateach end, the outer resonators of said set sidewise abutting opposedportions of the wall of said opening, and the upper ends of saidresonators being flush with each other and arranged between thehorizontal median of said opening and the upper end of the latter.

JOHN P. TRUESDEIL.

